Applicator or roller and method of making the same



1 R. R. LEWIS ET AL 2,333,800 I APPLICATOR OR RQLLER AND METHOD OFMAKING THE SAME .Original Filed Aug. 12, 1940 INVENTORS dcb f (d. W WmBY MUCH/W ATTORNEYS Patented Nov. 9, 1943 UNITED STATES PATENT SOFFICE 7APPLICATOR OR ROLLER AND METHOD OF MAKING THE SAME New York Originalapplication August 12, 1940, Serial No. 352,308. Divided and thisapplication May 23, 1941, Serial No. 394,355

. 3 Claims.

Our invention relates to-a new and improved applicator or roller whichcan be used as an ink-,-

ing roller on a printing press, as a roller in a coating machine forapplying lacquer, varnish, enamel and other purposes.

Our invention relates particularly to an inking roller or the like,which has a surface layer of an improved composition.

Another object of our invention is to provide an inking roller or thelike, which has a surface layer or peripheral layer which is soft,resilient, and resistant to the action of numerous solvents and liquids,such as oils, pyroxylin lacquers and other types of lacquers, varnishes,enamels, etc.

Other objects of the invention are stated in the annexed description anddrawing.

The drawing diagrammatically illustrates an inking roller or the likewhich is made according to the invention.

This roller has a core face layer 3.

While the invention is not limited to the ingredients or proportionsspecified herein, the fol- I, a body 2, and a sur- -lowing is given as apreferred formula for mak-' ing the surface layer 3:

Formula A Pounds -C stage Glyptal resiIi (1353U) 100 "Bakelite-Glyptalcasting resin (H529) 12.5

The C stage Glyptal resin is the essential ingredient of the mixture.This is a 52ft rubberlike resin and is one of the resins formed by theinteraction of glycerine-and polybasic organic acids which have eoine tobe known as Glyptal? resins or alkyd resins (see Synthetic Resins andTheir Plastics, by Ellis, 1923 edition, pages 293-298). In manufacturingthe resins which have been found satisfactory for this purpose,

the reaction is carried out in the presence of adipic acid. (Themanufacture of this type of flexible, resilient synthetic resin isdisclosed in U. S. Patent No. 1,897,260.) The proportion of 56 Themastication of the mill rolls, which are set,

adipic acid controls the hardness of the finished product. The resinwhich we prefer to use for most printing rolls requiring a soft face isdesignated by the manufacturer. General Electric Corporation, as #1353Uand is a mixture of fifteen parts of Glyptal resin and one part ofadipic acid. This mixture is suitably reacted with heat to bring it tothe C stage. Synthetic rubber which is made by polymerizing chloroprene,is also known under thename of duprene. As stated in vol. 2, p. 335, ofthe sup 'plement to Thorpes Dictionary 'of Applied Chemistry, publishedin 1935, duprene is chloroprene caoutchouc, which is obtained by thepolymerization of chloroprene.

The'compound is mixed on a regulation rubber mill using the followingprocedure:

The chloroprene polymer is put on the mill first and brought to aplastic condition, the wood rosin and coumarone resin, which serve assofteners are added first and thoroughly incorporated. The magnesiumoxide, which serves to stabilize the plastic chloroprene by neutralizingacidity, is incorporated next. The phenyl beta naphthylamine, which is astabilizer, and pine tar are addednext. The pine tar serves toaccelerate subsequent polymerization of the chloroprene polymer and alsoto mask its odor. Zinc oxide, whichserves as the chief accelerator ofsubsequent curing of the chloroprene, is added next. The two facticesand the cottonseed oil are added next. These materials also'serve assofteners for the chloroprene polymer. 'All of these ingredients arethoroughly incorporated with the chloroprene polymer and the batch isnow a soft plastic mass which can be readily handled on a rubber mill byone skilled in the art. This batch is now removed from the mill and setaside while the first two ingredients are mixed together. The castingresin is put on the mill first. This is a mixture of a phenolformaldehyde resin (Bakelite) and a B-stage "Glyptal resin. It is asoft, sticky mass of about the consistency of soft tar. It is a lightreddish tan in color. This material immediately smears all over the millrolls. The C-stage "Glyptal resin (1353U) which has been previouslyground to a uniform powder, is now dumped on the mill. This Glyptal"resin as made is in the form of rather firm. resilient, almosttransparent lumps. By repeatedly passing these lumps through a tightmill they are broken up into a powdery form similar in appearance towhite facticewhich has been ground by similartreat'ment.

tightly together, causes the "GlyptaP resin to be taken up by thecasting resin. As the mastication continues the mixture gradually formsa sheet which adheres to the back roll (fastest roll) of the mill. Theback roll must be equipped 5 with a scrape knife which is now used toproduce a homogeneous mixture. By scraping the sheet off the roll theentire amount of material is caused to pass through the mill rolls. Thisprocess is repeated several times until a uniform product results. Theoriginal batch which has been prepared with duprene is now put back onthe mill with the Glyptal" resin mixture and the whole batch isthoroughly milled together until homogeneous. The entire mixture nowreduprene" and the other materials, serves very 2o important purposes inthe material as finally manufactured. A material can be made from theGlyptalfresin and casting resin alone but such a material has severalserious shortcomings. Its

oil and solvent resistance'are splendid, -much greater than theresistance of rubber, but its stability and mechanical resistance arevery poor. It is very low in abrasion resistance, shearing resistanceand tensile strength. In other words it would be seriously damage byimpact with' the ends are bufied down to the core to give a sharp raisedsurfaces on a press. It would be unstable in the presence of heat andmoisture and liable to break down suddenly into a sticky mass having noserviceability whatsoever. The

chloroprene polymer mixture serves to stabilize the Glyptal resin. Itstrengthens and toughens the mixture and stabilizes it so that thedanger of dejelling mentioned above no longer exists.

The mixture made in accordance with the description given above is nowcalendered in prep- 40 aration for its application as the cover of aroll such as a printers roll. It is calendered on a regular three-roll.calender to any desired width and thickness. We prefer a thickness ofabout .040 to .050 inch run in one ply. If greater thickness is desiredit may be plied up in the regular manner in any desired thickness. Asthe mixture comes from the calender it is wrapped in a clean clothliner.

Rollers may be covered with this GlyptaP' mixture (Formula A) for theentire depth of coverage down to the metal core I or a base 2 of softrubber may be applied first and then a thin layer of Formula A appliedas an outside face covering -3, about one-eighth of an inch 5 thick. Thelatter procedure is desirable in most cases because of lower cost andgreater softness.

If the entire roll covering is made from Formula A, the metal core isprepared by first cleaning with a sand blast and then applying abrushcoat of a Bakelite" lacquer. The covering is then wrapped tightly aroundthe core spirally until the diameter is at least one-quarter inchgreaterthan the finished diameter desired.

Kraft paper is' wrapped around the roll and a sheet of galvanized ironisthen tightly applied, held in place with spiral wrapping of narrowfabric tape. The roll is'then heated in an atmosphere of hot air at atemperature of 300 F. for two hours. in a lathe to the finished diameterdesired and polished with fine emery cloth.

If only the surface stock is to be made from Formula A, it is necessaryto first cover the roll with rubber.

After cooling the roll is then buffed The following rubber compound 76serves as a satisfactory base. compound for soft rolls. This compoundmay be varied to produce rolls of dilferent firmness.

This ,compound is milled and calendered in the conventional manner inpreparation for building the roll. The metal core is cleaned bysandblasting and one ply of rubber compound which will vulcanize hard isapplied to bond firmly to the core. Sheets of Formula B calendered to athickness of about .075" are then wrapped in the form of a spiral aroundthe core until the diameter is about equal to the finished diameterdesired. A layer of paper is then applied followed by the application ofa sheet of galvanized iron tightly wrapped and held in place ,with

spiral wrappings of narrow fabric tape. This rollis then vulcanized byheating at a temperature of 278 F. for'four hours. After cooling theroll is buffed in a lathe to a diameter one-quarter inch less than thefinished diameter desired and length one inch less than the finishedlength desired. The surface is then painted with a solution of a fastcuring, tacky rubber compound. I After the solvent has evaporated, thesurface covering is applied using material-made in accordance withFormula A. The same procedure is used as that outlined in covering aroll without the rubber base except that the ends must be coveredwith'Formula A to prevent the oils and solvents from attacking therubber. Printing ink is usually linseed oil varnish, which attacksrubber. The ends are covered in the following manner: A strip of hardcuring rubber one-half inch wide is applied on each end, A strip-ofFormula A one inch wide is then wrapped on each end until the diameteris built up to the diameter of the rubber base. The entire surface isthen built up to a diameter one-quarterinch greater than the finisheddiameter desired. The roll is wrapped as described above and heated fortwo hours at 300 F. After cooling the roll is bufled in a lathe to thedesired length and diameter.

The procedure outlined above, using a rubber base, will produce a rollwhich will have a hardness of about 21 as determined by the ShoreDurometer. A roll built up solid from the core without a rubber basewill have a Shore hardness of about 25.- The softer roll will be moredesirable for some kinds of typographic printing but the harder rollwill suffice for printing from planographic plates and for some of thetypographic printing. The harder roll will also suffice for use as acoating machine roller where no indented surfaces are encountered or itwill serve as an inking roller for use with intaglio plates.

The proportion of the various softeningv ingredients incorporated withthe duprene influences the hardness to some extent, but as stated above,the hardness of the C stage Glyptal resin primarily determines thehardness of the finished roll. The Shore hardness test stated above isabout the lowest reading that can be obtained but it is possible toincrease this hardness to any extent desired.

In order to give practical examples of all the features of ourinvention, suitable formulas for i the hard rubber base and for thecementing compounds are as follows:

Formula for hard rubber base Pounds Smoked sheet 42.5 Zinc nxide 35Sulphur 22.5 Whole tire reclaim .15 Carbon b k Tetramethylthiurammonosulphide 1.25

Formula for fast curing tacky rubber compound which bonds the surface.compound to the rubber base Pounds Ounces Smoked sheet 52 Coumaroneresin 25 Sulphur 2 Y 3 Zinc oxide; 5 Whiting 10 Lithopone 10Tetramethylthiuram monosulphide Trimene base. 8

of the ingredients above mentioned, in making the protectivelayer orcoating, as a number of the ingredients mentioned in Formula A can beomitted without departing from the invention, since said formula isintended to represent the best embodiment of the invention.

0 acid.

It will be noted that the "duprene which is referred to in Formula A isadded to the remainder of the compound prior to the polymerizationthereof. This polymerization is produced by the 5 zinc oxide, during theheat treatment which is previously mentioned.

This application is a division of application Serial No. 352,308, filedAugust 12, 1940, on which U. S. Patent No. 2,243,386 has been issued onin May 27, 1941. Said application Serial No. 352,-

308 was a continuation in part of No. 688,584, filed September 8, 1933,and of No. 231,180, filed September 22, 1938.

We claim:

1. The method of making a printing roll which comprises windingon a coreprovided with a partially vulcanized soft rubber surface the requisitenumber of layers of a composition comprising alkyd resin and a plasticpolymer of chloroprene, securing the end surfaces'of the roll 'andtightly binding the outer of said layers with a porous covering,'vulcanizing in dry heat to the desired surface hardness, cooling,removing the coverings and machining the roller surface to 2. A printingroll comprising a core surfaced with a. resilient, rubber-like,oil-resistant layer of substantial thickness comprising the product ofvulcanization under heat of a composition containing alkyd resin, 9.plastic polymer of chlo-v roprene and vulcanizing agent.

3. A printing roll comprising a core surfaced with a resilient,rubber-like, oil-resistant layer of substantial thickness comprising theproduct of vulcanization under heat of a composition containing alkydresin, a plastic polymer of chloroprene and 'vulcanizing agent, saidalkyd resin being the product of reaction of glycerine, phthalicanhydride, glycol and dibasic aliphatic ,ROBERT R. ALBERT J. wmss.

